SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5078ffd3cea2a9598e71fb2f5c4a03211b5d9c9cffb3f31533c0f31d2e046287' 
  AND token = 'CL+ANkfvqPITBQSj7+zl3gY/DrQFJ4xb7QG/g8DC5ws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}